Capacitive touch panel having improved response characteristics

ABSTRACT

An apparatus is provided. The apparatus comprises a second layer disposed over a first layer. Each of the first and second layers have a set of detection electrodes that are spaced apart and electrically isolated from one another and an associated set of interleavers. Each interleaver is located between adjacent detection electrodes from its associated the set of detection electrodes, and each set of interleavers also includes a pair of complementary interleaving electrodes coupled to those that are electrically coupled to the adjacent detection electrodes from its associated set of detection electrodes. The detection electrodes and interleaving electrodes are also substantially transparent to visible spectrum light.

CROSS-REFERENCE TO RELATED APPLICATION

Under 35 U.S.C. §120, this continuation application claims priority toand the benefit of U.S. patent application Ser. No. 13/555,556, filed onJul. 23, 2012 and entitled “CAPACITIVE TOUCH PANEL HAVING IMPROVEDRESPONSE CHARACTERISTICS,” the entirety of which is incorporated hereinby reference.

TECHNICAL FIELD

The disclosure relates generally to a touch panel and, moreparticularly, to a capacitive touch panel having an improved response.

BACKGROUND

Turning to FIGS. 1 and 2, an example of a conventional system 100 can beseen. System 100 generally comprises a touch panel 102 and touch panelcontroller 104. The touch panel 102 has an array of sensors formed by aset of column electrodes (e.g., electrode 103), where each electrode ofeach column is coupled together by a strip electrode (e.g., stripelectrode 107), and a set of row electrodes (e.g., electrode 109), whereeach electrode of each row is coupled together by a strip electrode(e.g., strip electrode 107). Usually, the column and row electrodes(e.g., electrodes 103 and 105) are formed in two separate layers with adielectric or insulating layer formed therebetween, and these conductivelayers which form the electrodes (e.g., electrodes 105 and 109) aregenerally transparent to visible spectrum light (e.g., light having awavelength from about 380 nm to about 750 nm). The strip electrodes foreach column (e.g., strip electrode 107) are then coupled to theinterface or I/F 106 of the touch panel controller 104 by terminals X-1to X-N, while the strip electrodes for each row (e.g., strip electrode109) are coupled to the interface 106 by terminals Y-1 to Y-M. Theinterface 106 is able to communicate with the control circuit 108. Asshown in greater detail in FIG. 2, the interface 106 is generallycomprised of a multiplexer or mux 202 and an exciter 204.

In operation, the interface 106 (which is usually controlled by thecontrol circuit 108) selects and excites columns of electrodes (e.g.,electrode 103) and “scans through” the rows of row electrodes (e.g.,electrode 105) so that a touch position from a touch event can beresolved. As an example, interface 204 can excite two adjacent columnsthrough terminals X-j and X-(j+1) with excitation signals EXCITE[j] andEXCITE[j+1], and interface 106 receives a measurement signal from a rowassociated with terminal Y-i. When an object (e.g., finger) is inproximity to the touch panel (which is generally considered to be atouch event), there is a change in capacitance due at least in part tothe arrangement of electrodes (e.g., electrodes 103 and 105), and thecontroller 108 is able to resolve the position of the touch event.

Most conventional touch panels (e.g., touch panel 102) do, however,exhibit a non-uniform response characteristic, which is manifested asnon-uniform signal strength across the panel. This non-uniformity isgenerally caused by natural variations in the patterns forming thecolumn and row electrodes (e.g., electrodes 103 and 105). In otherwords, the electrodes are arranged to have gaps or non-overlappingregions between the electrodes so that, as an object (e.g., finger)traverses the panel (e.g., panel 102) and passes over thesenon-overlapping regions, the signal strength or measured capacitancechanges. Therefore, there is a need for a touch panel having a moreuniform response characteristic.

Some examples of other conventional systems are: U.S. Patent Pre-GrantPubl. No. 2011/0095996; U.S. Patent Pre-Grant Publ. No. 2011/0095997;U.S. Patent Pre-Grant Publ. No. 2011/0102361; and U.S. Patent Pre-GrantPubl. No. 2011/0157079.

SUMMARY

An embodiment of the present disclosure, accordingly, provides anapparatus. The apparatus comprises a first layer having: a first set ofdetection electrodes that are spaced apart and electrically isolatedfrom one another, wherein each detection electrode from the first set ofdetection electrodes is substantially transparent to visible spectrumlight; and a first set of interleavers, wherein each interleaver fromthe first set of interleavers is located between adjacent detectionelectrodes from the first set of detection electrodes, and wherein eachinterleaver from the first set of interleavers includes: a first set ofinterleaving electrodes that are electrically coupled to one of itsadjacent detection electrodes from the first set of detectionelectrodes, wherein each interleaving electrode from the first set ofinterleaving electrodes is substantially transparent to visible spectrumlight; and a second set of interleaving electrodes that are electricallycoupled to the other of its adjacent detection electrodes from the firstset of detection electrodes, wherein each interleaving electrode fromthe second set of interleaving electrodes is substantially transparentto visible spectrum light; and a second layer that is disposed over thefirst layer, wherein the second layer has: a second set of detectionelectrodes that are spaced apart and electrically isolated from oneanother, wherein each detection electrode from the second set ofdetection electrodes is substantially transparent to visible spectrumlight; and a second set of interleavers, wherein each interleaver fromthe second set of interleavers is located between adjacent detectionelectrodes from the second set of detection electrodes, and wherein eachinterleaver from the second set of interleavers includes: a third set ofinterleaving electrodes that are electrically coupled to one of itsadjacent detection electrodes from the second set of detectionelectrodes, wherein each interleaving electrode from the third set ofinterleaving electrodes is substantially transparent to visible spectrumlight; and a fourth set of interleaving electrodes that are electricallycoupled to the other of its adjacent detection electrodes from thesecond set of detection electrodes, wherein each interleaving electrodefrom the fourth set of interleaving electrodes is substantiallytransparent to visible spectrum light.

In accordance with an embodiment of the present disclosure, the firstlayer further comprises: a substrate that is substantially transparentto visible spectrum light; a conductive layer disposed over thesubstrate, wherein the conductive layer is patterned to form the firstsets of detection electrodes and interleavers; and an insulating layerdisposed over the conductive layer.

In accordance with an embodiment of the present disclosure, theconductive layer further comprises a first conductive layer, and whereinthe insulating layer further comprises a first insulating layer, andwherein the second layer further comprises: a second conductive layerdisposed over the first layer, wherein the second conductive layer ispatterned to form the second sets of detection electrodes andinterleavers; and a second insulating layer disposed over the conductivelayer.

In accordance with an embodiment of the present disclosure, the firstset of detection electrodes further comprises a first set of stripelectrodes that are substantially parallel with one another and areoriented in a first direction, and wherein the second set of detectionelectrodes further comprises a second set of strip electrodes that aresubstantially parallel to one another and oriented in a seconddirection, and wherein the orientation of the first and second sets ofstrip electrodes with respect to one another forms a plurality ofnon-overlapping zones.

In accordance with an embodiment of the present disclosure, the firstdirection is substantially perpendicular to the second direction.

In accordance with an embodiment of the present disclosure,complementary pairs of interleaving electrodes from at least one of thefirst and second sets of interleaving electrodes and the third andfourth sets of interleaving electrodes are located in eachnon-overlapping zone.

In accordance with an embodiment of the present disclosure, eachinterleaving electrode is substantially rectangular in shape.

In accordance with an embodiment of the present disclosure, eachinterleaving electrode is substantially triangular in shape.

In accordance with an embodiment of the present disclosure, the firstand second sets of strip electrodes further comprise first and secondsets of linear strip electrodes.

In accordance with an embodiment of the present disclosure, the firstand second sets of strip electrodes further comprise first and secondsets of diamond strip electrodes.

In accordance with an embodiment of the present disclosure, thecomplementary pairs of interleaving electrodes from the first and secondsets of interleaving electrodes and from the third and fourth sets ofinterleaving electrodes are located in each non-overlapping zone.

In accordance with an embodiment of the present disclosure, an apparatusis provided. The apparatus comprises a touch panel screen having a touchsensor disposed over a display, wherein the touch sensor has: a firstlayer having: a first set of detection electrodes that are spaced apartand electrically isolated from one another, wherein each detectionelectrode from the first set of detection electrodes is substantiallytransparent to visible spectrum light; and a first set of interleavers,wherein each interleaver from the first set of interleavers is locatedbetween adjacent detection electrodes from the first set of detectionelectrodes, and wherein each interleaver from the first set ofinterleavers includes: a first set of interleaving electrodes that areelectrically coupled to one of its adjacent detection electrodes fromthe first set of detection electrodes, wherein each interleavingelectrode from the first set of interleaving electrodes is substantiallytransparent to visible spectrum light; and a second set of interleavingelectrodes that are electrically coupled to the other of its adjacentdetection electrodes from the first set of detection electrodes, whereineach interleaving electrode from the second set of interleavingelectrodes is substantially transparent to visible spectrum light; and asecond layer that is disposed over the first layer, wherein the secondlayer has: a second set of detection electrodes that are spaced apartand electrically isolated from one another, wherein each detectionelectrode from the second set of detection electrodes is substantiallytransparent to visible spectrum light; and a second set of interleavers,wherein each interleaver from the second set of interleavers is locatedbetween adjacent detection electrodes from the second set of detectionelectrodes, and wherein each interleaver from the second set ofinterleavers includes: a third set of interleaving electrodes that areelectrically coupled to one of its adjacent detection electrodes fromthe second set of detection electrodes, wherein each interleavingelectrode from the third set of interleaving electrodes is substantiallytransparent to visible spectrum light; and a fourth set of interleavingelectrodes that are electrically coupled to the other of its adjacentdetection electrodes from the second set of detection electrodes,wherein each interleaving electrode from the fourth set of interleavingelectrodes is substantially transparent to visible spectrum light; and atouch panel controller that is electrically coupled to the first andsecond sets of detection electrodes.

In accordance with the present disclosure, the first set of interleavingelectrodes form a first set of first serpentines with its detectionelectrodes, and wherein the second set of interleaving electrodes form asecond set of serpentines with its detection electrodes, and whereineach first serpentine is interleaved with at least one secondserpentine.

In accordance with the present disclosure, the third and forthinterleaving electrodes form a zig-zag pattern the overlaps theinterleaved first and second serpentines.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIGS. 1 and 2 are diagrams of an example of a conventional system;

FIG. 3 is a diagram of an example of a system in accordance with thepresent disclosure;

FIG. 4 is a cross-sectional view of a touch panel of FIG. 3 alongsection line I-I;

FIGS. 5 and 6 are plan views of portions of the section of the touchpanel depicted in FIG. 4; and

FIGS. 7-20 are examples of the plan views shown in FIGS. 5 and 6.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are, for the sake ofclarity, not necessarily shown to scale and wherein like or similarelements are designated by the same reference numeral through theseveral views.

Turning to FIG. 3, an example of a system 200 in accordance with anembodiment of the present disclosure can be seen. System 200 is similarin construction to system 100 except that touch panel 102 has beenreplaced by touch panel 202. Additionally, interconnect 204 has beenprovided to provide communication channels between the touch panelcontroller 104 and the touch panel 202.

In FIG. 4, a cross sectional view for section 206 of touch panel can beseen. As shown in this example, the touch panel 202 is generallycomprised of a touch sensor 322 disposed over or positioned over adisplay 316 (which can, for example be a liquid crystal display or LCD)so as to allow the light from the display to project through the sensor322. This means that each layer of the sensor 322 is substantiallytransparent to visible spectrum light. As shown, the touch sensor 322 isa dual or two layer sensor, having a row layer 320, column layer 318,and cover plate 314. The column and row layers 318 and 320, in thisexample, each have a conductive layer 304 and 310 (respectively)disposed on a substrate 302 and 308 (respectively), but one of thesubstrates 302 or 308 may be used instead of two. Typically, thesubstrates 302 and 308 are formed of glass (which is substantiallytransparent to visible spectrum light), and the conductive layers 310and 304 are usually formed of a conductive material that is generallytransparent to visible spectrum light (such as indium tin oxide,aluminum doped zinc oxide, gallium doped zinc oxide, or indium dopedzinc oxide). Conductive layers 304 and 310 are also usually formed byelectron beam evaporation, physical vapor deposition (PVD), or sputterdeposition on the substrates 302 and 308, which can, for example, thenbe patterned using laser ablation or etching so to form the detectionelectrodes. The row and column layers 320 and 318 can then be secured toone another and the cover plate 314, using an insulating or dielectricmaterial (which can be an adhesive, like epoxy).

In order to achieve a more uniform response characteristic for the touchsensor 322, the patterns for the conductors 304 and 310 should bemodified. As shown in the example of FIGS. 5 and 6, row and columninterleavers 404 and 504 (respectively) are introduced between adjacentrows (e.g., rows 402-1 and 402-2) and adjacent columns (e.g., columns502-1 and 502-2) across the touch sensor 322. The interleavers (e.g.,404 and 504) can vary in configuration based on the shape orconfiguration of the conductors 304 and 310 but are intended to reducethe size (and, thus, the impact) of the non-overlapping zones andproduce a generally uniform response characteristic across the touchsensor 322.

In FIGS. 7-9, an example of an arrangement for the row and columninterleavers 404 and 504 is shown (which are labeled 404-A and 504-A,respectively) for section 206-A. In this example, row electrodes 402-A1and 402-A2 are combined with row interleaver 404-A so as to formserpentine electrodes that are interleaved with one another. The rowlayer 320-A can also (optionally) include floating regions (e.g.,floating region 406) interspersed between sections of the rowinterleaver 404-A, which can improve optical characteristics andresponse of the sensor (e.g., 322). Overlapping the row electrodes402-A1 and 402-A2 and row interleaver 404-A are the column electrodes502-A1 and 502-A2 and column interleaver 504-A that are arranged in azig-zag or “fishbone” pattern.

Turning to FIGS. 10-12, another example of an arrangement for the rowand column interleavers 404 and 504 (which are labeled 404-B and 504-B,respectively) for section 206 (which is labeled 206-B) can be seen. Forthis example, column electrodes 502-B1 and 502-B2 and row electrodes402-B1 and 402-B2 are linear strip conductors that are oriented indifferent directions so as to be perpendicular to one another. Becauselinear strip electrodes are employed, the non-overlapping region 602-Bis large. So, the row and column interleavers 404-A and 502-A are eachformed of complementary pairs of interleaving electrodes that are eachelectrically coupled to a corresponding electrode (e.g., 402-A1) andthat extend into the non-overlapping region 602-B. These complementarypairs of interleaving electrodes, however, remain electrically isolatedfrom one another. By doing this, the effect that the non-overlappingregion has on the performance of the touch sensor 322 can be greatlyreduced. Alternatively, as shown in FIGS. 13 and 14, all of thecomplementary pairs of interleaving electrodes do not need to be withinthe non-overlapping region (as shown with region 602-C), but some (e.g.,interleaving electrodes for column interleaver 504-C in column layer318-C) may be in proximity or substantially over/under correspondingelectrodes (e.g., row electrode 402-1) in a staggered pattern.

Additionally, as shown in FIGS. 15-17, the interleaving electrodes maytake a variety of shapes. With section 206-B and 206-C (which aredescribed above), the interleaving electrodes are substantiallyrectangular in shape, but it may be advantageous to employ other shapes.In the example shown in FIGS. 15-17, row interleaver 404-D and columninterleaver 504-D employ triangular shaped interleaving electrodes.

The interleaving electrodes may also be employed with various detectionelectrode shapes as well. In the example shown in FIGS. 18-20, thecolumn electrodes 502-E1 and 502-E2 and row electrodes 402-E1 and 402-E2are arranged as diamond strip electrodes (similar to the configurationshown with touch panel 102) that are oriented in different directions soas to be perpendicular to one another. In this example, the interleavingelectrodes for the column interleaver 504-E and row interleaver 404-Eare positioned on the edges of the diamonds in the column electrodes502-E1 and 502-E2 and row electrodes 402-E1 and 402-E2. This allows theperformance of a touch sensor 322 with good response characteristics(e.g., use of diamond strip electrodes) can be further improved.

Having thus described the present disclosure by reference to certain ofits preferred embodiments, it is noted that the embodiments disclosedare illustrative rather than limiting in nature and that a wide range ofvariations, modifications, changes, and substitutions are contemplatedin the foregoing disclosure and, in some instances, some features of thepresent disclosure may be employed without a corresponding use of theother features. Accordingly, it is appropriate that the appended claimsbe construed broadly and in a manner consistent with the scope of thedisclosure.

What is claimed is:
 1. A touch panel sensor comprising: a firstdetection electrode extending longitudinally; a second detectionelectrode extending longitudinally and parallel with the first detectionelectrode, the second detection electrode spaced apart and electricallyisolated from the first detection electrode; a first set of interleavingelectrodes extending from the first detection electrode withoutcontacting the second detection electrode; and a second set ofinterleaving electrodes extending from the second detection electrodewithout contacting the first detection electrode, the second set ofinterleaving electrodes interleaving with the first set of interleavingelectrodes.
 2. The touch panel sensor of claim 1, wherein the firstdetection electrode, the second detection electrode, the first set ofinterleaving electrodes, and the second set of interleaving electrodesare substantially transparent to visible spectrum light.
 3. The touchpanel sensor of claim 1, wherein: the first set of interleavingelectrodes are substantially perpendicular to the first and seconddetection electrodes; and the second set of interleaving electrodes aresubstantially parallel with the first set of interleaving electrodes andsubstantially perpendicular to the first and second detectionelectrodes.
 4. The touch panel sensor of claim 1, wherein the first setof interleaving electrodes from a first serpentine conductor with thefirst detection electrode, and the second set of interleaving electrodesfrom a second serpentine conductor with the second electrode.
 5. Thetouch panel sensor of claim 1, wherein each of the first and second setof interleaving electrodes is substantially rectangular in shape.
 6. Thetouch panel sensor of claim 1, wherein each of the first and second setof interleaving electrodes is substantially triangular in shape.
 7. Thetouch panel sensor of claim 1, further comprising: a first detectionlayer having: a first substrate substantially transparent to visiblespectrum light; and a first conductive layer disposed on the firstsubstrate and patterned to form the first and second detectionelectrodes and the first and second interleave electrodes in ahorizontal direction; and a second detection layer aligned with thefirst detection layer in a vertical direction perpendicular to thehorizontal direction, the second detection layer having: a secondsubstrate substantially transparent to the visible spectrum light; and asecond conductive layer disposed on the second substrate and pattern toform third and fourth detection electrodes partially overlapping withthe first and second electrodes along the horizontal direction.
 8. Thetouch panel sensor of claim 7, wherein: the third detection electrode issubstantially perpendicular to the first and second detection electrodesalong the horizontal direction and has a first extended electrodeextending parallel with the first and second detection electrodes alongthe horizontal direction; and the fourth detection electrode is arrangedparallel with the third detection electrode, the fourth detectionelectrode is substantially perpendicular to the first and seconddetection electrodes along the horizontal direction and has a secondextended electrode extending parallel with the first and seconddetection electrodes along the horizontal direction.
 9. The touch panelsensor of claim 8, wherein: the first extended electrode partiallyoverlaps with the first and second sets of interleaving electrodes alongthe horizontal direction; and the second extended electrode partiallyoverlaps with the first and second sets of interleaving electrodes alongthe horizontal direction.
 10. A display panel comprising: a displayscreen operative to project visible light; a first detection layervertically aligned with the display screen and substantially transparentto the projected visible light, the first detection layer having: afirst detection electrode extending longitudinally along a firsthorizontal direction parallel with the display screen; a seconddetection electrode extending longitudinally and parallel with the firstdetection electrode, the second detection electrode spaced apart andelectrically isolated from the first detection electrode; a first set ofinterleaving electrodes extending from the first detection electrodewithout contacting the second detection electrode; and a second set ofinterleaving electrodes extending from the second detection electrodewithout contacting the first detection electrode, the second set ofinterleaving electrodes interleaving with the first set of interleavingelectrodes; and a second detection layer vertically aligned with thedisplay screen and the first detection layer, the second detection layersubstantially transparent to the projected visible light and configuredto sense a touch event along a second horizontal direction substantiallyperpendicular to the first horizontal direction.
 11. The display panelof claim 10, further comprising: an insulation layer positioned betweenthe first detection layer and the second detection layer.
 12. Thedisplay panel of claim 10, wherein: the first set of interleavingelectrodes are substantially perpendicular to the first and seconddetection electrodes; and the second set of interleaving electrodes aresubstantially parallel with the first set of interleaving electrodes andsubstantially perpendicular to the first and second detectionelectrodes.
 13. The display panel of claim 10, wherein the first set ofinterleaving electrodes from a first serpentine conductor with the firstdetection electrode, and the second set of interleaving electrodes froma second serpentine conductor with the second electrode.
 14. The displaypanel of claim 1, wherein each of the first and second set ofinterleaving electrodes is substantially rectangular in shape.
 15. Thedisplay panel of claim 1, wherein each of the first and second set ofinterleaving electrodes is substantially triangular in shape.
 16. Thedisplay panel of claim 1, wherein the second detection layer includes: athird detection electrode isolated from and substantially perpendicularto the first and second electrodes, the third detection electrode havinga first extended electrode extending parallel with the first and seconddetection electrodes; and a fourth detection electrode isolated from andsubstantially perpendicular to the first and second electrodes, thefourth detection electrode having a second extended electrode extendingparallel with the first and second detection electrodes withoutinterleaving with the first extended electrode.
 17. A display systemcomprising: a display screen operative to project visible light; a touchpanel vertically aligned with the display screen and substantiallytransparent to the projected visible light, the touch panel having: afirst detection electrode extending longitudinally along a horizontaldirection parallel with the display screen; a second detection electrodeextending longitudinally and parallel with the first detectionelectrode, the second detection electrode spaced apart and electricallyisolated from the first detection electrode; a first set of interleavingelectrodes extending from the first detection electrode withoutcontacting the second detection electrode; and a second set ofinterleaving electrodes extending from the second detection electrodewithout contacting the first detection electrode, the second set ofinterleaving electrodes interleaving with the first set of interleavingelectrodes; and a control circuit coupled with the touch panel to detecta capacitance change in the first detection electrode and the seconddetection electrode.
 18. The display system of claim 17, wherein: thefirst set of interleaving electrodes are substantially perpendicular tothe first and second detection electrodes; and the second set ofinterleaving electrodes are substantially parallel with the first set ofinterleaving electrodes and substantially perpendicular to the first andsecond detection electrodes.
 19. The display system of claim 17, whereinthe first set of interleaving electrodes from a first serpentineconductor with the first detection electrode, and the second set ofinterleaving electrodes from a second serpentine conductor with thesecond electrode.
 20. The display system of claim 17, furthercomprising: a row detection layer having: a first substratesubstantially transparent to the projected visible light; and a firstconductive layer disposed on the first substrate and patterned to formthe first and second detection electrodes and the first and secondinterleave electrodes along a row direction; and a column detectionlayer vertically aligned with the row detection layer, the columndetection layer having: a second substrate substantially transparent tothe projected visible light; and a second conductive layer disposed onthe second substrate and pattern to form third and fourth detectionelectrodes partially overlapping with the first and second electrodesalong a column direction perpendicular to the row direction.